Machine for mixing concrete and other granular materials



April 9, 1935. N. HARRISON V 1,997,519

MACHINE FOR MIXING CONCRETE AND OTHER GRANULAR MATERIALS Filed Feb. 21, 1954 -2 Sheets-Sheet 1 llYVf/VTCA. NORMAN HARmso/v.

By Q/m f:

1977' ORA E X N. HARRISON April 9, 1935.

MACHINE FOR MIXING CONCRETE AND OTHER GRANULAR MATERIALS Filed Feb. 21, 1934 2 Sheets-Sheet 2 NORMAN Fig. 6.

HARRISON.

P......djl,...9,193 1 9 (UNI E- i smni si PATE TIQFF T fl p v inertia i v MACHINE FOR MIXING ooNoRE'rE A D OTHERHGRANULAR MA E IALS z I v Normangjl lafrison, England f i l Application l eliruary'21, 1934, Serial No. 712,421 2 I f In Great Britain January21, 1933 1 6 llaiinajj (o1. sar 13) This invention relates to machines for mixing at 2a to ensure its seating hard against the memconcreteand other granular materials of the her 3. j kind. comprising a rotary mixingpan having in A central spindle 4 (Figs. 3 and' l) projects the bottom of the pan-a centraljdischarge door. downwards from the 'dOOfZ" and is mounted in 5 consistingof arotary closure member mounted bearings 3, Sin ahousing'l'integral with an arm 5 torotate on one arm of-a leverso 'that by rock- 8 which is rigidly mounted on a shaft 9 extending I ing the lever in one direction the rotary member from the bottomof thepan I to, the side of the .iswithdrawn from the pan, while when thele'verunderfram'e l0 of the machine. On {the "outer is rocked in the other direction the rotary memend of thesh'aft 9 'arelatively long weighted arm l0 ber is brought into contact with the pan, c1oses- H is rigidly mounted at an angle such thatwhen l0 the opening and rotateswith the pan. I V t the door 2 is engaged with the opening in the The object of i the invention is to i provide a member 3 the arm I l is in a horizontal position so simple form of door of this'kind in which by one that the door is kept closed, while a lost motion movement only the closure member isfbrought connection between the arm H andthe shafts under the opening and efficient engagement of allows the former to passithe vertical position 15 the closure member with the opening always et: '.when the door is openedand so maintain it open fectedirrespective of the relative positions of the as indicatedindotted lines in -Figs. l and 2.

pan'and, the closuremember while at the same With this'arrangementwhen "itis desired to time ensuringthe opening: always being sealed c1ose-thefdoor,*there being only smoo'th engagirrespective, of wear and with the closuremem ing'surfaces'between the door Zandthe opening 20 beralwaysoutof theway; sothat inaddition to inthe"pan ;the door maybe closed without any it beingjjpossible to take full advantage of theh special care being exercised to ensure proper en space abovethepan; the mixing means may be gagement between theclosure device and the V arrangedtowork over the; door. openingwhile owing to theconicalform of the According, to the inventionthe lever arm -on two memberszande and 'eifective seal is always 25 which the closure member is mountedis *itmaintained irrespective of wear;a1though after self-pivotally=- mounted about a stationary fulaI-periodfof wear' it may-be found necessary to crum below the pan, so that to operate the door plane the top of the door 2 to bring it tosub to bring it under and into the opening, and vice stantially the same level as the floor of the pan. I.

versa, the lever is rocked only, the said closure The shaft 9 is shown connected by lever and 30 member being in the form of a truncated cone, link mechanism to avertically slidable deflector and theopening in the pan correspondingly tablade I! in such a manner that when thedoor pered so that the closure member and the pan is opened thefisaid blade is lowered, and vice may engage after the manner of a cone clutch. versa. This device does not form part of the The invention will now be described-by way of present invention, and need not be described 35 example with reference to the accompanying further here. Fora full description reference drawings, which show a portion of a concrete is made to my co-pending patent application No.

, mixer comprising a circular discharge door. In 712,422, filed 21st February, 1934.

the said drawings: I V V In order to ensure the door 2 evenly engaging 40 Fig. 1 is a side elevation. the opening in the member 3, the housing 1 may 40 Fig. 2 is an end elevation. i be mounted to float in a gimbal supported from Fig. 3 is a sectional elevation to an enlarged the arm 18. This willallow the door 2 to adapt scale showing the door more in detail. itself to any eccentricity or other irregularity Fig. 4 is a plan of Fig. 3. t t t between itself and the opening. 1 a

Fig. 5 is a diagrammatic view in elevation show- In .a modification, the opening and the 010- 45 ing an alternative means for raising and lowersure member may be of slightly oval form with ing the door. the inner edge of the closure member of such di- Fig. 6 is an end view of Fig. 5. mensions that it will always enter the opening.

Referring more particularly to the drawings, I; This form gives combined positive and frictional is the mixing pan and2 acircular closure member engagement between the opening and closure 50 I or door of tapered section; adapted to fit into a member. l V t r a correspondingly tapered opening in a circular According to another arrangement the arm flanged member 3fitting concentrically under a of the closure member may be arranged to move central opening in the pan I. The tapered face in ahorizontal plane or at a small angle to the 5 ofxthe door 2 iscut away at its mid-portion as horizontal, so that the door is made to move together and pivotally mounted at one end about a horizontal axis l5, whilermeans, not shown,

are provided for tilting the tracks M to and from the openingrin the member 3.- A stop 15 limits the outward travel of the carriage |,3,.

With this arrangement, to close the door the tracks IE are tilted by the tiltinggear until the door2 engages in the opening in the members The" door is opened by lowering thetilting gear, and then drawing the carriage l3 along the tracks M out of range of the opening.

I claim:'- v a V 1. In a machine for mixing concrete and other granular materials of; the kinddescribed, com

prising a rotary mixing pan having acentra-l dis charge opening of truncated conicai section, a

lever arm pivotally mounted on astationaryi'ulcrum below said pan, the axis of said fulcrum being transverse to the axisof the central discharge opening, a rotaryclosure member of corresponding truncatedconical section adapted to fit into said discharge opening when it is desired'toclose said opening, and means for mounting said rotary closure'on' saidlever arm tor being transverse to the axis of the central dismovement along saidlever arm. r

2..' In a machine for mixing concrete and'other granular materials of'the kmd described, comprising arotary'mixing pen having a central discharge opening of truncated conical section, a lever arm pivotally mounted on a stationary fulcrum below said pan, the axis of said'iulcrum chargeopening, a rotary closure member of cor-- responding truncated conical section adapted to fit into said discharge opening when itis desired to close said opening, a track on said lever arm extendingtransversely of said discharge opening, a carriage movable along said track, and

carriage.- r r means forrotatably mounting said closure on said carriage. i 1

3. In a mixing machine of the character described, a mixing pan having an opening therein, a stationary fulcrum positioned adjacent the opening in the pan and having its axis arranged perpendicular to the axis of said opening, a lever rockably mounted on said fulcrum for swinging movement toward and away from said'opening, a closure for said opening, and means for mounting said closure on said lever for movement along said lever.

4. In a;,mixing machine of the character described,'a mixing pan having anopening therein, a stationary fulcrum positionedadjacent the 7 opening in the pan andhaving its axis arranged perpendicular to the axis of said opening, a lever rockably-mounted on said fulcrumior swinging movement toward and away from said opening,

a closure for saidopening, a track on said lever, a carriage movable along said track,;and means for mounting said closure on said carriage. 1 5. In .a mixing machine'of thei-characterde scribed, a mixing pan having an openingin the bottom thereof, a fulcrum positioned beneath said pan and laterally spaced from said opening, said fulcrum having its axis perpendicular to the axis of said opening, a lever rockablyv mounted on said fulcrum for swinging movement to and from a position; directly underneath said, open ing, a closurefor said opening,'and meansfor mounting said closure on said lever for movement along saidleveril-v iY 6. In a mixing machine -01 thefcharacter described, a mixing pan having an opening in the 7 bottom thereof, a fulcrumpositioned beneath said pan and iateraliy spaced from said opening,

said fulcrum ha l ng its axis perpendicular to the axis of said opening, a lever rockably mount-1 ed on said fulcrum for swingingmovement to and from a position directly underneath said opening, a, closure. for .said opening, a track on said lever, a carriage movable alongsaid track, andmeans for mounting said closure oni said NORMAN HARRISON. 

